/Engine/Plugins/FX/Niagara/Source/NiagaraEditor/Public/ViewModels/NiagaraSystemViewModel.h
Returns a multicast delegate that is broadcast when an emitter pinned state has changed
[FOnPinnedEmittersChanged](API\Plugins\NiagaraEditor\ViewModels\FNiagaraSystemViewModel\FOnPinnedEmitter-) & GetOnPinnedEmittersChanged()